TY - JOUR
T1 - Latex agglutination assays for detection of non-O157 Shiga toxin-producing Escherichia coli serogroups O26, o45, O103, O111, O121, and O145
AU - Medina, Marjorie B.
AU - Shelver, Weilin L.
AU - Fratamico, Pina M.
AU - Fortis, Laurie
AU - Tillman, Glenn
AU - Narang, Neelam
AU - Cray, William C.
AU - Esteban, Emilio
AU - Debroy, Chitrita
PY - 2012/5/1
Y1 - 2012/5/1
N2 - Latex agglutination assays utilizing polyclonal antibodies were developed for the top six non-O157 Shiga toxin-producing Escherichia coli (STEC) serogroups. Rabbit antisera were affinity purified through protein A/G columns, and the isolated immunoglobulins (IgGs) were covalently immobilized onto polystyrene latex particles. The resulting latex-IgG complex had a protein (IgG) load of 0.20 to 0.28 mg/ml in a 1% latex suspension. Optimum conditions for the agglutination assay consisted of utilizing 20 ml of latex-IgG reagent containing 2.0 to 2.8 mg IgG in a 0.5% latex suspension. Agglutination or flocculation was observed almost instantly after mixing the colonies with the latex-IgG, indicating STEC strains. More than 100 target and nontarget strains were tested in more than 3,000 test replicates. All target organisms produced positive results, but three antisera (anti-O26, anti-O103, and anti-O145) cross-reacted with some other STECs. The anti-O103 and anti-O145 latex reagents crossreacted with O26 strains, and the anti-O26 cross-reacted with O103 strains. The latex-IgG reagents are stable for at least 1 year and are easy to prepare. These agglutination assays can be used for identification of presumptive non-O157 STEC colonies from agar media. The techniques used to prepare the latex reagents also can be utilized for testing other STEC serogroups, other E. coli serotypes, or other pathogens to ensure safe foods to consumers.
AB - Latex agglutination assays utilizing polyclonal antibodies were developed for the top six non-O157 Shiga toxin-producing Escherichia coli (STEC) serogroups. Rabbit antisera were affinity purified through protein A/G columns, and the isolated immunoglobulins (IgGs) were covalently immobilized onto polystyrene latex particles. The resulting latex-IgG complex had a protein (IgG) load of 0.20 to 0.28 mg/ml in a 1% latex suspension. Optimum conditions for the agglutination assay consisted of utilizing 20 ml of latex-IgG reagent containing 2.0 to 2.8 mg IgG in a 0.5% latex suspension. Agglutination or flocculation was observed almost instantly after mixing the colonies with the latex-IgG, indicating STEC strains. More than 100 target and nontarget strains were tested in more than 3,000 test replicates. All target organisms produced positive results, but three antisera (anti-O26, anti-O103, and anti-O145) cross-reacted with some other STECs. The anti-O103 and anti-O145 latex reagents crossreacted with O26 strains, and the anti-O26 cross-reacted with O103 strains. The latex-IgG reagents are stable for at least 1 year and are easy to prepare. These agglutination assays can be used for identification of presumptive non-O157 STEC colonies from agar media. The techniques used to prepare the latex reagents also can be utilized for testing other STEC serogroups, other E. coli serotypes, or other pathogens to ensure safe foods to consumers.
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U2 - 10.4315/0362-028X.JFP-11-430
DO - 10.4315/0362-028X.JFP-11-430
M3 - Article
C2 - 22564929
AN - SCOPUS:84860823953
VL - 75
SP - 819
EP - 826
JO - Journal of Food Protection
JF - Journal of Food Protection
SN - 0362-028X
IS - 5
ER -